tracing/probes: Fix to add NULL check for BTF APIs

Since find_btf_func_param() abd btf_type_by_id() can return NULL,
the caller must check the return value correctly.

Link: https://lore.kernel.org/all/169024903951.395371.11361556840733470934.stgit@devnote2/

Fixes: b576e09701 ("tracing/probes: Support function parameters if BTF is available")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu (Google) 2023-07-25 10:37:19 +09:00
parent 6eaae19807
commit 1f9f4f4777

View File

@ -386,12 +386,12 @@ static const struct btf_type *find_btf_func_proto(const char *funcname)
/* Get BTF_KIND_FUNC type */
t = btf_type_by_id(btf, id);
if (!btf_type_is_func(t))
if (!t || !btf_type_is_func(t))
return ERR_PTR(-ENOENT);
/* The type of BTF_KIND_FUNC is BTF_KIND_FUNC_PROTO */
t = btf_type_by_id(btf, t->type);
if (!btf_type_is_func_proto(t))
if (!t || !btf_type_is_func_proto(t))
return ERR_PTR(-ENOENT);
return t;
@ -443,7 +443,7 @@ static int parse_btf_arg(const char *varname, struct fetch_insn *code,
if (!ctx->params) {
params = find_btf_func_param(ctx->funcname, &ctx->nr_params,
ctx->flags & TPARG_FL_TPOINT);
if (IS_ERR(params)) {
if (IS_ERR_OR_NULL(params)) {
trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
return PTR_ERR(params);
}
@ -1273,7 +1273,7 @@ const char **traceprobe_expand_meta_args(int argc, const char *argv[],
params = find_btf_func_param(ctx->funcname, &nr_params,
ctx->flags & TPARG_FL_TPOINT);
if (IS_ERR(params)) {
if (IS_ERR_OR_NULL(params)) {
if (args_idx != -1) {
/* $arg* requires BTF info */
trace_probe_log_err(0, NOSUP_BTFARG);